wifi and cdwriter problems

[Luca Ferrari]

Hi all,
I'm using 8.04 (k)ubuntu on a compaq nc8430 laptop and I'm noting strange 
issues:
1) the wifi card is not working if disabled at boot time. The bluetooth (that 
starts with the wifi switch) works, but if I turn on the wifi card after the 
boot programs like knetworkmanager cannot see the card.
2) the cdwriter often is not available, and k3b claims about that. After a 
reboot the cdwriter is agai available, and after another reboot it is no more 
available and so on.

What can I do to solve this problems?

Thanks,
Luca